Problem: Simplify the following expression: $x = \dfrac{1}{2t} - \dfrac{1}{6t}$
Solution: In order to subtract expressions, they must have a common denominator. The smallest common denominator is the least common multiple of $2t$ and $6t$ $\lcm(2t, 6t) = 6t$ $ x = \dfrac{3}{3} \cdot \dfrac{1}{2t} - \dfrac{1}{1} \cdot \dfrac{1}{6t} $ $x = \dfrac{3}{6t} - \dfrac{1}{6t}$ $x = \dfrac{3 -1}{6t}$ $x = \dfrac{2}{6t}$ Simplify the expression by dividing the numerator and denominator by 2: $x = \dfrac{1}{3t}$